(ORDO NEWS) — We have exciting new evidence that Venus is geologically active.
Using radar images taken by the Magellan spacecraft in the early 1990s, scientists discovered the volcanic vent, which changed shape and grew in eight months. period in 1991.
This is one of the most compelling clues that volcanism is still active on Venus, shaping the planet’s surface and atmosphere.
This affects how we interpret observations of our neighboring planet, including the detection of phosphine gas, originally attributed to potential life, but it could also be the result of volcanic activity.
“We are studying volcanic regions on Venus that were imaged two or three times by Magellan and are identifying an approximately 2.2 km 2 volcanic vent that changed shape in the eight months between two radar images,” writes geophysicist Robert Herrick of the University of Alaska Fairbanks. and engineer Scott Hensley of NASA‘s Jet Propulsion Laboratory in California.
“We interpret this s result as ongoing volcanic activity on Venus.”
Venus and Earth have a lot in common; their size, mass, density and composition are very similar. But for two identical pieces of rock, they definitely went their separate ways.
The land is moist, temperate and teeming with life. Venus is dry, terribly hot, and enveloped in a poisonous, suffocating, and turbulent atmosphere.
Another difference between the two planets is the lithosphere, a rocky outer shell containing a viscous molten interior.
The Earth’s lithosphere is like a cracked eggshell, consisting of many pieces, tectonic plates, the edges of which rub against each other. Most of the Earth’s volcanic activity occurs along these boundaries.
The lithosphere of Venus is a single solid shell without tectonic plates. This raised questions about the planet’s volcanic activity.
Its young surface is evidence of a recent volcanic revival, but whether it is still volcanically active, and how active, remains an open question.
Venus’s atmosphere makes it difficult to see its surface; this requires imaging techniques that can cut through the dense layer of carbon dioxide.
Other probes have flown past Venus and taken pictures, but in order to understand any potential volcanism, you need something that can control the surface in time.
This is where Magellan comes to the rescue.
He spent just under 4.5 years orbiting Venus, using radar to image the surface for most of that time, between 1990 and 1992.
However, the probe’s orbit was elliptical, which means that the different angles at which it displayed the surface of Venus made the data obtained unsuitable for automatic comparative analysis.
This meant that a person had to do it manually, which is a time-consuming and painstaking task.
“It’s only really been in the last decade or so that Magellan data has become available in full resolution, tiled and easily manipulated by an investigator from a typical personal workstation,” explains Herrick.
First, he narrowed down the data he needed to review by selecting areas previously identified as likely volcanic. He then manually scanned the Magellan images looking for changes in the landscape around these areas.
And he found something close to the two largest volcanoes on Venus, Ozza and Maat Mons. These volcanoes are comparable in volume to volcanoes on Earth, but are flatter and spread out.
Between February and October 1991, the vent on the north side of the shield volcano, which is part of Mount Maat, noticeably changed shape.
Initially, the mouth was almost round, its area was about 2.2 square kilometers. which is slightly larger than Monaco. In a later image, the shape was larger, about 4 square kilometers, and irregular.
It also appeared to be nearly filled to the brim, possibly becoming a lava lake, although it is not clear if the material inside it was still melted by the time of the second image.
The shape of the area around the vent has also changed, possibly as a result of fresh lava flows. Hensley ran simulations and found that volcanic activity was likely.
Perhaps the vent collapsed on its own, in the absence of volcanic activity; but here on Earth, such collapses always occur as a result of volcanic activity, either locally or nearby.
Combined with other recent studies, including a careful examination of the Magellan data, the results provide strong evidence of ongoing volcanic activity near Earth’s closest planetary neighbor.
And some intriguing research opportunities for Venus probes currently in development.
“Now we can say that Venus is currently volcanically active in the sense that there are at least a few eruptions a year,” says Herrick.
“We can expect upcoming Venus missions to observe the new volcanic flows that have occurred since the completion of the Magellan mission three decades ago, and we should see some activity taking place as the two upcoming orbital missions gather images.”
Contact us: [email protected]